title: Meiotic recombination in Arabidopsis is catalysed by DMC1, with RAD51 playing a supporting role.
abstract: Recombination establishes the chiasmata that physically link pairs of homologous chromosomes in meiosis, ensuring their balanced segregation at the first meiotic division and generating genetic variation. The visible manifestation of genetic crossing-overs, chiasmata are the result of an intricate and tightly regulated process involving induction of DNA double-strand breaks and their repair through invasion of a homologous template DNA duplex, catalysed by RAD51 and DMC1 in most eukaryotes. We describe here a RAD51-GFP fusion protein that retains the ability to assemble at DNA breaks but has lost its DNA break repair capacity. This protein fully complements the meiotic chromosomal fragmentation and sterility of Arabidopsis rad51, but not rad51 dmc1 mutants. Even though DMC1 is the only active meiotic strand transfer protein in the absence of RAD51 catalytic activity, no effect on genetic map distance was observed in complemented rad51 plants. The presence of inactive RAD51 nucleofilaments is thus able to fully support meiotic DSB repair and normal levels of crossing-over by DMC1. Our data demonstrate that RAD51 plays a supporting role for DMC1 in meiotic recombination in the flowering plant, Arabidopsis.
authors.affiliation: Génétique, Reproduction et Développement, UMR CNRS 6293 - Clermont Université - INSERM U1103, Aubière, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Da Ines
authors.forename: Fabienne
authors.initials: F
authors.lastname: Degroote
authors.forename: Chantal
authors.initials: C
authors.lastname: Goubely
authors.forename: Simon
authors.initials: S
authors.lastname: Amiard
authors.forename: Maria E
authors.initials: ME
authors.lastname: Gallego
authors.forename: Charles I
authors.initials: CI
authors.lastname: White
mesh_terms: D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics*; D002875:Chromosomes / Q000235:genetics; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D008540:Meiosis; D051135:Rad51 Recombinase / Q000235:genetics*; D011938:Rec A Recombinases / Q000235:genetics*; D011995:Recombination, Genetic / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C513034:ATDMC1 protein, Arabidopsis; C495146:ATRAD51 protein, Arabidopsis; D051135:Rad51 Recombinase; D011938:Rec A Recombinases